Catalysts comprising cobalt on a support such as silica or alumina are known to be useful in hydrogenation reactions such as hydrogenating aldehydes and nitrites. They are also used in hydrocarbon synthesis via the Fischer-Tropsch process.
Promoter metals, such as rhenium, zirconium, manganese and the like, are commonly used with cobalt to improve various aspects of catalytic performance.
In the case of the Fischer-Tropsch hydrocarbon synthesis process, especially ashen conducted in a slurry bubble column reactor, the preferred catalyst comprises cobalt supported on a titania support. Generally, the titania in such catalysts is in its rutile form.
In US Patent Publication 2004/0204506 A1, which is incorporated herein in its entirety, there is disclosed an improved catalyst support comprising primarily titania, converted from its anatase form to its rutile form, and a minor amount of a binder comprising cobalt aluminate. The cobalt aluminate is incorporated in the rutile titania support by forming the titania support with an alumina binder and thereafter reacting the alumina binder with a sufficient amount of a cobalt compound to convert at least part and preferably substantially all of the alumina to cobalt aluminate. Typically, a small amount of cobalt titanate is formed as well. For convenience, this support is referred to herein as the “titanate support.” Catalysts comprising cobalt, rhenium or a mixture thereof on the “titanate support” have demonstrated improved selectivity for producing higher hydrocarbons in the Fischer-Tropsch process.